I'm adding a round table animation to a 3d model and by default (when I apply the animation for the first time) it works as expected: the 3d model spins around a its centre point.For some reasons at some point, the pivot point seems to move, and the rotation doesn't spin around its centre any longer.

Do you know why is this, where are the setting to control and change the pivot point and how to re-set it to the centre point of the 3d model?